Motor-starter.



V. M. HARRIS.

MOTOR STARTER. VAPPLIUATION IILED AUG.24,1912. RENBWED Nov. z. 1914. 1 120,6 1 6 Patented DBC. 8, 1914.

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y ZU-Q/ZZT 76mm L @ZJ/@www V. M. HARRIS.

MOTOR STARTER.

APPLICATION 111.1111 111111.24, 1912.. RENEWBD No1/.2. 1914.

Patented Dec. 8, 1914.

3 SHEETS- SHEET 2.

- V. M. HARRIS.

MOTOR STARTER. APPLIGATION FILED 2112.24, 1912. RBNEWED Nov. 2, 1914.

1,120,61 6. Patented De0.8,1914.

3 SEEE S-SHEET 3.

-r 106 706 EJO? '7 5 60 @Q l UNITED sTATEs PATENT oEEioE.

vanuit 1c. mams, or c HmAGo, 11.1.1NoIs .assmnon 'ro HENRY s. Hnlwm, A

TRUSTEE, orjcnrcneo, runners.

MOTOBFSTABTER.

Patented Dea-8,1914.

Application med August 21,1912, serial no. 716,809. Renewed November 2,1914. semi 1ro. 889,973.

Toall whom z't may concern.'

Be it known that I, VARIAN M. HARRIS, .a citizen of the United. States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Motor- Starters, ofwhich the followin isa specication.

My invention re ates to motor starters, and refers particularly, thoughnot exclusively, to starters used for synchronous motors.

In my co-pending application,A Serial No. 629,466, led May 25, 1,911, Ihave described a type of synchronous motor which isiparticularly adaptedfor use with a. rectifying commutator for the purpose. of convertingalternating current into unidirectional pulsating current. n

My present invention, relating to motor starters, is particularlyadapted for use in connection with the motor which has been described inthe above-mentioned application, and which I shall again describe ingeneral terms in the present application in order that the operation ofthe starter may be clearly understood.

According to the provisions of my invention, the rotor of my motor issuitably started, by mechanical means or otherwise, vand the fields are.intermittently energized in such manner that the speed ofthe rotorincreases until synchronism isreached. When this condition results, asuitably controlled governor effects certain changes in the electriccircuit controlling the field so that normal operation of the motor iseffected, and it is retained in synchronism with the source ofalternating current. After synchronism has been attained, I providemeans by which the circuit which is temporarily closed through the fieldby means of the governor is permanently closed, and the motor thencontinues to run at synchronous speed entirely independently of theaction of the governor.

As further objects of my invention I provide apparatus in connectionwith my starter by which suitable electric connections are made toenable my motor to be used with a rectifying commutator. Means are alsoprovided for indicating when the rotor has attained synchronous speed,and further means to indicate the polarity of the unidirectional current.which flows from the rectify/ing commutator.

These and other advantages ofm invenrepresent a preferred embodiment ofmy invention, and in which- Figure is.. a plan ofmy improvedv motor,showing ,thev starter applied thereto; Fig. 2 is a side elevation ofthe-upper part of my motor, showing the starter in posit1on; F1g. 3 is abottomplan of my motor, the lower part of the field casing being brokenaway in order to show the automatic governor; Fig. Ziis a horizontalsection on the line 4-4 of Fig. 2, but with the cams rotated to adilerent position from that in which they are shown in Fig. 2; and Fig.5 1s a diagram showing the wiring used in connection with my starter andthe motor and rectifying commutator with which the starter is adapted tooperate.

Thev motor with which my invention is particularly adapted to be usedconsists of a field casing lOhaving the poles 11, each of which is-provided with va Apole piece 12'. The field casing 10 is provided, withan upper spider 13 and a lower spider 14.v The upper spider 13 hasconnected therewith the bear- 1n member 15.

ounted on the rotor shaft 16 are a Series of laminated plates which aresuitably shaped to form the rotor pole pieces 17, these pole piecesbeing preferably of the same number as the pole pieces 12 of the field.Also mounted on the rotor shaft 16 is a rectifying commutator 18,comprising a plurality of conducting segments 18, and

kalternating with these the conducting segments 181. The segments 18aare electrically connected with the slip ring 19 and the segments 18hwith the slip ring 20 by means of conductors passing through the body ofthe commutator 18. p

Engaging the commutator 18 are the commutator brushes'21 and 22, thesebrushes being held by the brush holders 23 and 24 respectively. Each ofthe brush holders is pivotally mounted on a pin 25, and is normallymoved by the spring 26 into a position in which the brush is held inengagement with the commutator 18.

Mounted on the field casing 10 is the illar 27, on which is rigidlymounted the fiame 28, through which passes the spring-controlled stop29, the object of which will be explained hereafter. Attached to theframe tached the operating handle y37. 1'5

" .Y the 38,hav`ing mounted thereon the post ing Ithroughfthe"sleeve isa rod 42, carry-- 28 is a guide frame 304 havin apertures thereinthrough Vwhichpass a ro 31 leading to the brush holder 23 vand a secondrod 32 leading to the brush holder 24; Rotatably mounted on the pillar27 and having cams 33wand 34 so asto be vrotatable there- .with isthe'drum`35, of insulating'material. lAttachedtovthe lupper'end .of thedrum 35 is the face plate.36,1to which'is rigidly at- .,Extendingfrom'the upper spider-13 is 39l which hasl :rotatably mounted-on its endthe sleeve-40, 'the rotationof which, is con-v trolled( bythe--s'pringl14L' The objectief this 'i Spring .wiii -be-expMindhereafter- Pass" ing thereon the dog'43, whichfis adapted to,

-engage'the teeth 4oi thestarting wheel '44 rigidly mounted on"` therotor sha t engagesthe 'teeth' ofthe starting wheel 44 wheirthe is movedto the proper position, as wiilpresently be explained. The

vso..

I 46,'fwhich engages 'onone'end 'the sleeve 40 shown in Fig.lbytheaction4 of the spring `-aiidjon'the. other end'the block 47carried. on

ltherod 421 'so' that the collar 48 on `the rod .is brought intoengagement with the'jen'd L 4 2 is mounted thej'member v'49,('whiclivextends .over the face plate. 36 and has'therein a notch which Aislengaged by the '.51v

mounted on the face plate 36. 1 .l t ,l The post'52 wl'ii h-"is mountedon the'iield casing 10carriesthecontactjholders 53, 54,

' 55.4 and ,'56, whiChcarry, "respectively, "the 50' "'sivelybrought'into contact with the contacts 57 58, 59 -and 60 as the drum 35is 'rotated' spring, contacts ,58,1 59"'and 60.` These i s ring'contactsengage the periphery of the ruin'35.' Mounted'` on the drum 35 are theconducting segments 61,' 62, 63 and64, which are included intheelectriccircuits which will presently Ybe described. -As shown in Fig.2, the segments 61, 62, 63 and 64 arefof' different lengths so that theyare succesina clockwise direction by means of the jhand1e37. l Thegovernor which is used in connection with my linvention is illustratedin Fig: 3. .Itinay bev placed Vin any convenient position on the rotor.lshaft 16, but in my motor I prefer'topla'ce it below the laminatedplates which' form the rotor. The governor 65 is pivotallyf'attached tothe post 66 mounted on the disk 67,v which is of insulating material,andm'ay. be fastened to the rotorjby anysuitable means, as, for example,by the screws'68. At its end the governor'65 is itsbearing against theframe 28 is a cam 33,1 and rigidly connected with .this cam` is alsecond Scam 34'. .Also rotatably mounted on j `.the pillar27 andvrigidly connectedwith the 16. carried by thelrod is a brush 45, which.rod 42,v is normally moved into the position provided with the ball orweight 69, to which is attached the spring anchored at its opposite endto the disk -67 through the instrumentality of the adjustable p yoke 71andscrew `72. On the governor 65 is the V.contact 73 adapted to engagethe contact 74 on .the end of the screw 75 which is held in adjustedposition in the post 7 6'by means of Through-i the instrumentality ofslip rings and brushes, orby any other suitable well known means, which,-for the vsake of simplicity, have not been shown 4'in the drawings, Vanelectrical connection ismade' on the one hand with the ,post 66to'whichthe governor 65 is pivotally attached, and

on the other hand to'thel post 76. The cir-- cuitsemployed with theseconnections will be explained detail hereafter.

The operation' ofi' my lstarter 'willnow be explained particularly inconnection-with -the diagram'shownin Fig. 5'.' Alternating current fromAany suitable' source passes 'throughl the` main conductors 78 and79.

The switch 80 is adapted to connect the conductor-78 with the conductor81 and theconductor 79 with 'the conductor 82. When v it is desired tostart the motor, the' handle 37 isrotated in a clockwise direction,where- .1,

by the pin 51 lon the face plate 36 carries'- the 4rod 42 forward and atthe same time inwardly toward the starting wheel 44, so" i that the dog43 engages one of the teeth of this wheel and rotation of the rotorshaft 16 begins. The cam 33 is, of course, moved with the drum 35, andis provided with a y series ofrecesses in its lower surface, which areengaged by the springcontrolled stopl 29 sothat the various positions ofthe 'starting device are easily determined and after ibe- 'its ingdetermined may be readily maintained. vWhen the handle 37 is moved intothe posi' the brush 45, while thevconductor 85 connects theconductor-:83 with the brush`45, ,120'.

while the conductor 86 leads from conductor 83 to the post 66 to whichthe governor 65 is attached. When the brush'45 is in contact with one ofthe teeth-.of the starting wheel 44 duringrotation ofthe latter, thecurrent passes from the .'main conductor 78 through the switch' 80 tothe conductor 81, and thence through the spring contact v57, the segment61the conductors 83 and 85, and the brush 45, to the wheel 44, andthence pieces 12. f brought into positions opposite the polepieces.

the poles 1l ofthe motor field. After passing through these windings,lthe current passes tthrough conductor 88 tothe conductor -82, andthence through the switch 80 to themain conductor 7 9, thereby complet-linghthe circuit. When thewheel 44 isin suc the teeth of the wheel, andelectricalconnection with-the latter is thereby broken, the currentafter reaching the conductor 83 passes to the lamp 84, and thencethrough the conductor 89 to te windings of the poles l1 of the field ofthe motor, and thence, throu h ythe conductor 88 to the conductor 82,rom which passes through. the switchl 8O to the main conductorI 79.

It will fbe evident thatl when the circuit is as justedescribed, thelamp 84 will be lighted, but on vaccount of the resistance offered bysaid lamp the energization of the coils of the'poles 11 will becomparatively slight. The wheel 44 is so disposed on'the vrotor shaft 16that the brush 45 will be inlenga. ement with the teeth of the wheel 44wile the pole pieces 17 of the rotor approach the pole pieces 12 of thefield poles 11 after they pole pieces 17 have passed then-positionsmidway between the pole When the pole pieces 17 are 12, however, theelectrical connection between .the brush 45 and the -itartin wheel 44xisbroken, vand is not again ma e until the .pole pieces 17 have. again.passed midway. position between thel pole pieces 12. It will be evidentthat inA this way the motor acts as an attraction motor, andthe speed ofthe rotor is constantly increased until the contact 73 of the governor 65 is brought into engagement with the contact 74 in electricalconnection withv the turn,is connected with conductor 9 0 bytheconductor 91.- TheconductorQO is connected-at 92 with the conductor87, so that when they circuit. is closed through the governor ISISv thecurrent flows from conductor 83, through conductor 86, 'governor 65,conductors 91, 90'and`87, ,to theI coils of the field poles 11,y andthence through the, conductors 88 and 82.through the switch ductor 79,The tension of the'spring 70 andthe position of thejcontact 74 varesoadjusted that the contact 73 engages the contact 74 when the speed ofrotation of the rotor issyn'- chronous with the .alternationsgof themain current,or slightly in excess thereof. After the circuitis closedthrou h the governor vno current will iiow throng the vlamp-84, so

that the latter will become extinguished. The lamp 84, therefore, actsA.as ameans for indicating Vwhen the rotor has been-brought.intosynchronism with the main current.

, position that lthe. brush 45 is betweenthe current then Ament .63.Inasmuch -as lt post 76, which, in v to the main con` therebycompleting the circuit.

alternating current Aftersynchronisin. has. been attainedand the 84indicatiig this conditionis .extinguished, the han e 37 s moved imaclockwisedirection into ositionNo. 2. The pin 51v thereby becomes.-isengaged fromtha. member 49, so thatfthe spring 46;causesthe. rod 42tobemovedto bring-the-.collar48 spring contact 58 be ng connectedwithfcon-f I duetorV 8 1, the current. now 'passes from con.- ductor-8lthrough contact 58, segment 62, and con uctor .to-conductor 87 andthence through, the, sainel path'. :as scribed, back @to th The-circuitwhich is ernor ..65 opens. and closes Several times the circuit which-it controls. Thev handle -37 is next/moved in a clokwise. .direction toposition, No. .3, -fwhereby thej spring 59 is broughtinto engagementlwith the sege' contactb58 still remains. an ,engagement Wth-Ethersegment 62, it ;will be evident. thatthecireuit controllingthe coilsofthefeld .will remain closed.v The effect. of bringing the contact 59into en agementlwiththesegment' is.

to establis an entirely new circuit,- where.- by that portion of themain alternating current/which is to vbe 'rectiiedis brought to therectifying commutator. The current flows from the conductor 8l throughspring contact 59, segment' 63, and r.conductor 94 to the brush 95,which engages one of the slip r}i1ngs,1for example-,'the'sl1p ring `19.,From t is si mutator 1 8. The brush 96 fis connected with conductor.82, and engagesthe 4slip ring 20, which, as previouslyexplaned, isconnected with the second series of alternate previously; de-v efmamconductor 79.'- now established is the permanent equivalent .o :thecircuit which., is temporarily closed'by means of the' gov-.- ernor.Itioften happensI thatfbefo're. the rotor is brought4 intoexactsynchronisln with --the main source ring the currentpasses to one.series o alternate-segments 18% ofthe co1n of current, thegov.- Y

contact segments 18b voi the commutator 18. The

is 'convertedinto unidirectional current at the commutator 18, currentof one polarity l passing through the brush 22 and conductor 97, andcurrent of the opposite polarity passing throu h brush 21 and conductor99. Assuming t at the double-throw switch passing to the slip rings`conductor 102 and through fuse 103, placed lamp 105 and conductors 106and 107 te the 'terminal 108,-.tc which'f-is at-l tacherhby asuitableconductor, one'.v le'o av stcragebattery 116 or theflike. T e current;after passing tery returns through the contact 109, and thence passesthrough conductor y1.10 containing the fuse 1131, to

vthe switch 101 and through said switch tov the conductor 99, therebycompleting the .cir cuit.' It -is wellknown that in charging fa storagebattery the current owing to the battery must be in oppositionto thecurrent which the battery tends to generate. If the charging is notperformed in this manner, the battery would b'e rapidly dischargedinstead of being charged. c

Assume that the electromotive force of the battery is 70 volts, and thatthe electromotive force of the current flowing from the commutator 18 is110-volts'at the peaks of the' phase' waves. It will now be evident thatif the brushes 22 and 21 are connected with a storage battery throughthe various conductors which'v have been mentioned so that the chargingcurrent is not counter to the current tending to flow from the battery,

lamp 105 would be 180 volts. If the lamp 105 is of the ordinary'220-volttype, it will therefore be evident that this lamp` would burn brightly,whereas if the electromotive force of the unidirectional current fromthe commutator 18 is `in opposition to the current of the storagebattery, the eiiective electromotive force would be only 40 volts, sothat the llamp 105 would burn dimly.

When the starter is in position No. 3, which we have just described, itwill be clear that the current flowing between the storage battery andthe commutator 18 must pass through the resistance of this lampdeterioration of the battery by too rapidly exhausting the same(provided the flow of current from therecti'- tying commutator 18 is notin opposition to that of the battery) is prevented.

If the lamp 105 burns brightly, the switch 101 is then moved into itsalternate position so that current from the conductor 97 passes throughconductor 112, through switch 101, and conductor 110 to the terminal109. yAfter flowing through the baty tery the current then passesthrough vconductors 107 and 106 to lamp 105, and thence throughconductors 104 and 102 to switch 101, from which it passes throughconductor 113 to conductor 99.. In other words, when the switch 101 isin its first position the current from the commutator 18 Hows to thebattery in one direction and when the switch 101 is placed in its secondposition rent flows in the opposite direction,

the curthereby throughthe storage baty a suitable conductor to theeective electromotive force acting on lamp 105, and on account ofthe nclarity of the current flowing from the recti er to the battery.

When the starting device ,is in'po'sitions i f Nos. land 2 the cams 33and 34 are i'n such position that the rods 31 and 32 are held by ytheperipheries of these cams so that the brushes 21 and 22 are held out ofcontact with the commutator 18; but when osition No. 3 of the startingvdevices is lreac ed, the

rods31 and 32 are allowed to move into the recesses 114 and 115 of thecams 34 and 33,

whereby the brushes 21 and 22 are allowed to come in contact with thecommutator 18.

ghesel positions of the cams are indicated in After the swath 101 hasbeen adjusted in such position that the lamp 10,5-,burns dimly,

No. 4. The ends of the rods 31 and 32 stilll remain in the recesses 1.14and 115, thereby still maintaining'the commutator brushes 21l and 22 incontact with the commutator 18.

The spring 'contacts 57, 58 and 59 also still remain in engagement withtheir respective segments 61, 62 and 63, and the spring contact 60 isnow brought into engagement with the segment 64. Assuming thatthe switch101 is inlcontact with the switch terminals 98 and 100, it Vwill beevident that current from the conductor'v 97 after reaching theconductor 104 will pass alongsaid conductor to the segment l 64, andthence through the spring contact 60 and conductor 106 to the conductor107 instead of passing through the lamp 105, vas was the case when thestarter was in position No. 3'; Similarly, if the switch 101 is in itssecond position, the current from conductor 99 after passing throughconductor 113 follows the path just described. Whcr'the starter has beenmoved to position No. 4, all conditions are such that the Ymotor isadapted to runindefintely. The rotor of the motor is maintained insynchronisrn with the main source of alternating current by theutilization of a small percentage of said current, while the mainportion of the alternating current is converted the handle 37 is movedto position.

into unidirectional pulsating .current and used for the charging of astorage battery or other similar purpose.

It will be clear to those skilled in' the art that many changes could belmade in the detailed construction of the various'v parts which I havedescribed without departing from the spirit orscope ofmy invention.

VVha-t I claim is:

1. A starter for synchronous motors, coniprising the combination with asource of alternating current of means for intermittently connectingsaid source with the eld winding of said. motor during predeterminedportions o the revolution of the rotor, whereby the speed of said rotoris increased, and governing means for automaticallyconnecting saidsource with said field Winding during the entire revolution of saidrotor when the speed of the latter approximates that of synchronism,thereby bringing the rotor into synchronism with said sourcesubstantially as described.

2. A starter for synchronous motors, com- Vprlsing the combination witha source of alternatlng current of means for starting the rotation ofthe rotor, means for intermittently connecting said source -with thefield winding of said motor during predetermined portions of therevolution of the rotor, whereby the speed of said rotor is increased,and governing means for automatically connecting said source with saidfield winding during the entire revolution of said rotor when the speedof the latter approximates that of synchronism, thereby bringingtherotor into sychronism with said source, substantially as described.

3. A starter for synchronous motors, comprising the combination with asource of alternatlng current of means for intermittentlyconnecting'said source of alternating current with the field winding ofsaid motor during predetermined portions of the revolution of the rotor,whereby the speed of said rotor is increased, governing means forautomatically connecting said .source with said field winding during theentire revolution of said rotor when the speed ofthe latter approximatesthat of synchronism,there by bringing the rotor into synchronism withsaid source, and means for permanently connecting said source with saidfield winding, whereby the rotor is maintained in synchronism with saidsource, substantially as described.

4. A starter for synchronous motors, comprising the combination with asource of alternating current of means for starting the rotation of therotor, means for intermittently connecting said source with the fieldwinding of said motor during predetermined portions of the revolution ofsaid rotor, whereby the speed of the latter is increased, governingmeans for automatically connecting said source with said field windingduring the entire revolution of said rotor when the speed of the rotorapproximates that of synchronism, thereby bringing said rotorinto'synchronism with said (permanently connecting field winding,whereby source, means for said source wlth sal the rotor is maintainedin synchronism with said source, and means for breaking the intermittentconnection between said source and said field windin when said permanentconnection is estag as described.

5. A starter for synchronous motors, comprising the combination with asource of alternating current of a startin Wheel having a plurality ofteeth and adapted to be mounted on the rotor shaft, actuating means forengaging said wheel, whereby the rotation of said rotor is started, abrush adapted for engagement with the teeth of said starting wheel,means for connecting said brush with said source of alternating current,vmeans for connecting said starting wheel with the field 4.of saidmotor, whereby said field winding may be connected with said sourceduring engagement of said teeth by said brush, t ereby increasing thespeed of said rotor, and governin means for automatically connecting saifield winding with said source when a predetermined rate of speed isreached, thereby brin g said rotor into synchronism with sai source,substantially as described.

6. A starter for a synchronous motor having a rectifying commutator,comprising the combination with a source of alternating current of meansfor starting the rotation of the rotor, means for intermittentlyconnecting said source with the field wlnding of said motor duringpredetermined portions of the revolution of the rotor, whereby the speedof the latter is increased, governing means for automatically connectingsaid source with said field winding during the entire revolution of therotor when the speed of said rotor approximates that of synchronism,thereby bringing said rotor into synchronism with said source, means forpermanently connecting said field winding with said source, whereby saidrotor is maintained in synchronism with said source, and means forconnecting the current recti ying means of said rectifier with saidsource, whereby a pulsating unidirectional current may be conducted romsaid rectifier, substantially as described.

VARIAN M. HARRIS.

Witnesses:

HENRY M. HUxLEY,

. E. HANNEN.

lished, substantiallyA

